Loader bucket with push plate ejector



United States Patent Eddie B. Wagner Portland, Oregon Dec. 23, 1968 Dec. 1, 1970 Wagner Mining Scoop, Inc. Portland, Oregon a corporation of Oregon Inventor Appl. No. Filed Patented Assignee LOADER BUCKET WITH PUSH PLATE EJECTOR 7 Claims, 2 Drawing Figs.

US. Cl 214/767, 214/146 Int. Cl E021 3/70 Field of Search 214/767, 146(E), 510, 82; 37/103, 117.5, (B.C.)

[56] References Cited 7 UNITED STATES PATENTS 2,852,869 9/1958 Beyerstedt 214/510X 3,122,248 .2/1964 Campbell et al 214/510X FOREIGN PATENTS 121,428 4/1948 Sweden ..2l4/l46(E)UX Primary ExaminerI-lugo O. Schulz Attorney-Lee R. Schermerhorn ABSTRACT: An open bottom bucket is equipped with a jointed push plate ejector which, when retracted, forms the bottom of the bucket. Actuation of the push plate ejects the load without the necessity of tilting the bucket downward to the usual gravity discharge position whereby the bucket may discharge at a higher level than conventional buckets. Also; the push plate provides a mobile platform spanning the mouth of the bucket to give workmen convenient access to the roof ofa mine or tunnel.

Patented Dec 1, 1970 Sheet L or 2 INVENTOR. EDDIE B. WAGNER Patented Dec. 1, 1970 Shoot 1 LOADER BUCKET WlTH'PU SI-I'P LATE EJECTOR BACKGROUND OF THE INVENTION This invention relates to improvements in a loader bucket and has particular reference, to a novel push plate ejector for ejecting a load without tilting the bucket downward to the usual gravity discharge position.

A loader bucket is a scooping bucket or shovel pivotally mounted on a forwardly extending boom on a vehicle. The bucket is filled by tilting it forward and lowering the boom and then driving the vehicle forward toward a pile of material, causing the lip of the bucket to penetrate the'pile and fill the bucket. The bucket is then erected to retain the load during travel to a dumping station. In conventional practice, the bucket is dumped into a truck or mine car by raising the boom and tilting the bucket forward to a steep angle for gravity discharge of its contents.

When the bucket is of large size, the conventional-gravity dumping manipulation may require more overhead clearance than is available in a mine ortunnel at the place where the bucket is filled. This often requires the vehicle to travel a considerable distance to dump the load. Much time and expense would be saved if the bucket'coul'd dischargeits load into a truck or mine car without requiring so much overhead clearance.

Objects of the invention are, therefore, to provide a loader bucket which will discharge its contents at a'relatively' high v SUMMARY orrua INVENTION The present push plate is of jointed construction allowing it to move to a retracted position where it forms the bottom of the bucket. In its actuating movement, cam and roller devices reduce sliding friction and wear on the bucket, making the mechanism durable and reliable. By discharging the load with the front wall of the bucket in horizontal position instead of tilted downward, a high discharge level is achieved without requiring the usual high overhead clearance.

When the push plate is fully extended, it spans the mouth of the bucket to provide a mobile platform for workmen operating on the roof of a mine or tunnel and for other purposes. The height of the platform is adjustable by merely raising and lowering the boom.

The invention will be better understood and the foregoing and other objects and advantages will become apparent from the following description'of the preferred embodiment illustrated in the accompanying drawings. Various changesmay be made in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view of a loader vehicle, with parts broken away, having a bucket embodying the principles of the invention, the bucket being shown in different positions in broken lines; and

FIG. 2 is a similar viewof the front portion of the vehicle, with parts broken away, showing details of construction and showing the bucket in different positions in broken lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT Although the present bucket may be mounted on different kinds of vehicles, there is shown by way of example a common type of loader vehicle having a front body section l pivotally connected at 11 with a rear body section 12 for steering. Body section is supported on a pair of front wheels 13 and body section 12 is supported on a pair of rear wheels 14. Hydraulic steering cylinders 15 are controlled by a steering wheel 16 at the operator's station. An engine in rear body section 12 drives the wheels 13 and 14 and operates a hydraulic pump to supply a hydraulic pressure system connected with various hydraulic cylinders which will be'described.

Bucket'20 is pivotally mounted at 21 on the forward end of a boom 22. The rear end of boom 22 is pivotally mounted at 23 on front-body section 10. The boom is raised and lowered by a pair of hydraulic cylinders 25 having pivotal connection 26 at their lower ends on body. section 10. Cylinders 25 contain piston rods'27 having pivotal connections 28 with the boom. The boom is shown in its lower position in full lines in FIGS. land 2. Extension of piston rods 27 raises the boom to an upper position 220 shown in broken lines in FIGS. 1 and 2.

A cylinder 30 is provided for leveling the bucket as the boom moves up and down and fortilting the bucket to various positions on its boom pivots 21. The rear end of cylinder 30 is pivotally connected at 31 with body section 10. The cylinder contains a piston rod 32 having pivotal connection at 33 with a link '35 as best shown in FIG. 2. The front end of link 35 is pivotally connected at 36 with a bracket 37 on the back of the bucket.

Link 35 is described in detail in my.U.S. Pat. No. 3,29 l ,3 30, issued Dec. 13, 1966. In brief, this link has a rear end 38 overhanging the piston rod 32 behind pivot 33, preventing the link from pivoting upward on the piston rod but allowing it to pivot downward. When the piston rod and link are not under tension, the rear end 38 of the link permits the joint at pivot 33 to drop by gravity to a slightly overcenter position, locking the joint so that the piston rod may exert thrust against the bucket for diggingwhen the vehicle is driven forward.

This digging or scooping position of the bucket is shown at 20a in FIG. 2. When the boom is raised, link 35 allows an unusually large range of pivotal movement of the bucket for dumping by conventional gravity discharge as illustrated by the bucket position 2012 in FIG. 1. By breaking the joint at pivot 33, the link 35 wraps around the bottom of the bucket to assume an angular position in relation to piston rod 32. In such position, the link and piston rod are under tension, The low position of bucket lip 40 in position 20b and the high position of the back of the bucket illustrate the height limitations in conventional dumping by gravity discharge of the bucket. With such a large bucket, a low tunnel roof does not permit dumping into a truck or mine car whereby the bucket can only bedumped on a low level conveyor belt or opening in the floor.

Referring now to FIG. 2, the bucket has a front wall 41 which extends from lip 40 to a lower edge at 42. A back wall 43 extends from the top of the bucket to a lower edge at 44. The bottom of the bucket between lower edges 42 and 44 is 'open. The'primaryfeature of the invention comprises a jointed push plate having a back plate section with pivotal connection 51 at its lower edge with a bottom plate section 52.

The push plate is actuated by a pair of cylinders 55 pivotally connected at 56 with brackets 57 on the bucket backwall 43. Cylinders 55 contain piston rods 60 pivotally connected at 61 with hollow brackets 62 on the forward side of push plate secto form a bottom in the bucket. In this position, the front edge of push plate section 52 rests on a stop 70 near the lower end of front wall 41. Plate sections 50 and 52 extend the full length of the bucket between its vertical end walls 69. Section 50 is approximately vertical and section 52 is approximately horizontal when the bucket is erected with its mouth in horizontal position as shown in full lines in FIG. 1.

The under side of push plate bottom section 52 is equipped with curved cam plates 71 arranged to engage rollers 72 on brackets 73 mounted on the lower end of bucket frontwall 41. Alternatively, the rollers may be mounted on plate 52 and the cam plates 71 mounted on the bucket wall 41. When piston rods 60 are extended, push plate section 50 swings counterclockwise away from backwall 43, causing bottom section 52 to move outward toward the mouth of the bucket along front wall 41 as shown in broken lines in FIG. 2. It will be apparent that, without the rollers, the large angle between plate section 52 in its solid line position and front wall 41 of the bucket would create sliding friction between these parts of such great magnitude that section 52 could not be moved away from stop 70 or that, if it could be moved, objectionable wear would occur between the sliding surfaces.

This difficulty is overcome by cam plates 71 and rollers 72 which provide easy, low friction movement push plate section 52 in its initial range of movement away from stop 70. The

fore and aft dimension of section 52 and the shape of cam.

plates 71 are such that the front edge of section 52 moves up to point 75 on front wall 41 with relatively light pressure against the front wall or even with slight clearance, if desired. Throughout this initial range of movement, the entire load on plate section 52, or substantially the entire load, is brought to bear on rollers 72 instead of front wall 41.

When the front edge of push plate section 52 reaches point 75, cam plates 71 leave the rollers 72, allowing the front edge of plate section 52 to bear against front wall 41. From point 75 almost to lip 40, plate section 52 is at a favorable angle to front wall 41 so that the front edge of the plate will slide with tolerable friction and without objectionable wear on front plate 41. At point 75 the angle between plate section 52 and front wall 41 is somewhat less than 45. This angle diminishes as the bulk of the load is discharged and then increases again near the end of the movement.

Movement of the push plate sections 50 and 52 toward the mouth of the bucket ejects the load with front wall 41 in approximately horizontal position. The boom may be at any desired height as indicated by the different bucket positions at c and 20d in FIG. 2. Thus, while operating under limited overhead clearance, as indicated by vertical dimension 80, the bucket may still be discharged at a relatively high level over the side of a truck or mine car as represented by the vertical dimension 81. Vertical dimension 82 in FIG. 2 indicates the relatively short distance below the tunnel roof at which the load may be discharged.

FIG. 1 illustrates how the ejector plate sections 50 and 52 may be utilized as a mobile platform for workmen. When adjusting the height of the boom, this platform may be raised and lowered through the vertical range designated by dimension 83. This convenience obviates the necessity for auxiliary equipment to enable the workmen to reach the tunnel roof as is routinely necessary for prying off loose rocks and other purposes. The more auxiliary equipment that can be eliminated from the cramped space in a mine or tunnel, the moie expeditiously the work can proceed.

Iclaim:

1. In a loader vehicle a boom, means for raising and lowering said boom, a bucket pivotally mounted on said boom, means for rotating said bucket on said pivotal mounting between forward tilted scooping and dumping positions and an erected position in which the mouth of the bucket is horizontal, a jointed ush plate ejector having a flat back plate section and a flat be torn plate section, pivot means connecting the upper edge of said back plate section with an upper back portion of the bucket, pivot means connecting the lower edge of said back plate section with the rear edge of said bottom plate section, and cylinder and piston means connected between the back of the bucket and said back plate section arranged to swing both of said sections into horizontal position with the front edge of said bottom plate section moving along the front wall ofthe bucket and coming to rest on the lip ofthe bucket forming a workmen's platform across the mouth of the bucket above said boom when the mouth of the bucket is horizontal.

2. A vehicle as defined in claim 1, said back plate section being approximately vertical and said bottom plate section being approximately horizontal when said ejector is retracted and the mouth of the bucket is horizontal.

3. A vehicle as defined in claim 1, the connection between said cylinder and piston means and the back of the bucket being at a lower level than the connection between the cylinder and piston means and said back plate section in all positions of said back section when the mouth of the bucket is horizontal.

.4. A vehicle as defined in claim 1, the bottom of the bucket being open and said bottom plate section of said ejector closing said open bottom.

5. A vehicle as defined in claim 1 including astop on said front wall supporting said front edge of said bottom plate section of said ejector in retracted position.

6. A vehicle as defined in claim 1 including cam and roller means on said bucket and said bottom plate section of said ejector arranged to guide the movement of said bottom plate section along said front wall of the bucket.

7. A vehicle as defined in claim 6, said cam and roller means comprising cam plates on the under side of said bottom plate section, and rollers on the lower edge of said bucket front wall engageable with said cam plates. 

